/***************************************************************************
 *   Copyright (c) 2019 Werner Mayer <wmayer[at]users.sourceforge.net>     *
 *                                                                         *
 *   This file is part of the FreeCAD CAx development system.              *
 *                                                                         *
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU Library General Public           *
 *   License as published by the Free Software Foundation; either          *
 *   version 2 of the License, or (at your option) any later version.      *
 *                                                                         *
 *   This library  is distributed in the hope that it will be useful,      *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU Library General Public License for more details.                  *
 *                                                                         *
 *   You should have received a copy of the GNU Library General Public     *
 *   License along with this library; see the file COPYING.LIB. If not,    *
 *   write to the Free Software Foundation, Inc., 51 Franklin Street,      *
 *   Fifth Floor, Boston, MA  02110-1301, USA                              *
 *                                                                         *
 ***************************************************************************/


#ifndef BASE_CONVERTER_H
#define BASE_CONVERTER_H

#include <tuple>
#include "Base/Rotation.h"
#include "Base/Vector3D.h"


namespace Base {
    template <class vecT>
    struct vec_traits { };

    template <>
    struct vec_traits<Vector3f> {
        using vec_type = Vector3f;
        using float_type = float;
        vec_traits(const vec_type& v) : v(v) {}

        std::tuple<float_type, float_type, float_type> get() const {
            return std::make_tuple(v.x, v.y, v.z);
        }

    private:
        const vec_type& v;
    };

    template <>
    struct vec_traits<Vector3d> {
        using vec_type = Vector3d;
        using float_type = double;
        vec_traits(const vec_type& v) : v(v) {}

        std::tuple<float_type, float_type, float_type> get() const {
            return std::make_tuple(v.x, v.y, v.z);
        }

    private:
        const vec_type& v;
    };

    template <>
    struct vec_traits<Rotation> {
        using vec_type = Rotation;
        using float_type = double;
        vec_traits(const vec_type& v) : v(v) {}

        std::tuple<float_type, float_type, float_type, float_type> get() const {
            float_type q1, q2, q3, q4;
            v.getValue(q1, q2, q3, q4);
            return std::make_tuple(q1, q2, q3, q4);
        }

    private:
        const vec_type& v;
    };

    // type with three floats
    template <class _Vec, typename float_type>
    _Vec make_vec(const std::tuple<float_type, float_type, float_type>&& t) {
        using traits_type = vec_traits<_Vec>;
        using float_traits_type = typename traits_type::float_type;
        return _Vec(float_traits_type(std::get<0>(t)),
                    float_traits_type(std::get<1>(t)),
                    float_traits_type(std::get<2>(t)));
    }

    // type with four floats
    template <class _Vec, typename float_type>
    _Vec make_vec(const std::tuple<float_type, float_type, float_type, float_type>&& t) {
        using traits_type = vec_traits<_Vec>;
        using float_traits_type = typename traits_type::float_type;
        return _Vec(float_traits_type(std::get<0>(t)),
                    float_traits_type(std::get<1>(t)),
                    float_traits_type(std::get<2>(t)),
                    float_traits_type(std::get<3>(t)));
    }

    template <class _Vec1, class _Vec2>
    _Vec1 convertTo(const _Vec2& v) {
        using traits_type = vec_traits<_Vec2>;
        using float_type = typename traits_type::float_type;
        traits_type t(v);
        auto tuple = t.get();
        return make_vec<_Vec1, float_type>(std::move(tuple));
    }
}

#endif // BASE_CONVERTER_H
